Song had been strongly linked to the Catalan club leading up to the 2012-13 English Premier League season and he did not appear in Arsenal’s scoreless draw against Sunderland to open league play.

This is the second consecutive summer in which Barça has bought a talented, young and productive Arsenal central midfielder. Last August, the Blaugranabought back Cesc Fabregas, who came up through the team’s heralded youth program.

This deal comes shortly after Robin van Persie exited Emirates Stadium for a £24 million move to Manchester United, as reported by the BBC’s David Ornstein.

Following Song and van Persie’s departures, Arsene Wenger must find a way to replace his most productive set-up man and his leading goal-scorer. Song finished the season with 11 assists, while van Persie led the Premiership with 30 goals.

The Gunners brought in Lukas Podolski, Olivier Giroud and Santi Cazorla during the transfer window. All three of these players saw the pitch in Arsenal’s first league fixture.

It will be an ongoing storyline this season if the young talent on Arsenal’s roster and these new players will be able to keep the team playing at a high level. Wenger has never allowed the North London club to fall below fourth place, but a cluster of talented teams in the top half of the table and the absence of two of his best players from a season ago will make this a challenging campaign.